In this note, we are concerned with delay-dependent stability of high-order delay systems of neutral type. A bound of unstable eigenvalues of the systems is derived by the spectral radius of a nonnegative matrix. The nonnegative matrix is related to the coefficient matrices. A stability criterion is presented which is a necessary and sufficient condition for the delay-dependent stability of the systems. Based on the criterion, a numerical algorithm is provided which avoids the computation of the coefficients of the characteristic function. Under some conditions, the presented results are less conservative than those reported. A numerical example is given to illustrate the main results.
In this paper, we are concerned with numerical methods for linear neutral systems with multiple delays. For delay-dependently stable neutral systems, we ask what conditions must be imposed on linear multi-step methods in order that the numerical solutions display stability property analogous to that displayed by the exact solutions. Combining with Lagrange interpolation, linear multi-step methods can be applied to the neutral systems. Utilizing the argument principle, a sufficient condition is derived for linear multi-step methods with preserving delay-dependent stability. Numerical examples are given to illustrate the main results.
In this paper, we are concerned with stability of numerical methods for linear neutral systems with multiple delays. Delay-dependent stability of Runge-Kutta methods is investigated, i. e., for delay-dependently stable systems, we ask what conditions must be imposed on the Runge-Kutta methods in order that the numerical solutions display stability property analogous to that displayed by the exact solutions. By means of Lagrange interpolation, Runge-Kutta methods can be applied to neutral differential systems with multiple delays. Based on the argument principle, sufficient conditions for delay-dependent stability of Runge-Kutta methods combined with Lagrange interpolation are presented. Numerical examples are given to illustrate the main results.
We studied delayed effects of elevated plasma levels of corticosterone (Cort) on volumetry, neuronal quantity, and gross marks of neurodegeneration in the hippocampal formation of Long-Evans rats. Animals were exposed to increased CORT levels for three weeks via implanted subcutaneous pellets. Volumetry, neuronal quantification and gros s marks of degeneration were measured seven weeks after the termination of CORT treatment. We observed significant differences in volumes and especially in laterality of hippocampal subfields between control and CORT- treated animals. We found th at the left hippocampus was substantially larger than the right hippocampus in the corticosterone-treated group, but not in the control group. In the control group, on the other hand, right hippocampal volume was markedly higher than all other measured volumes (hippocampal left control, hippocampal left CORT-treated and hippocampal right CORT-treated). Left hippocampal volume did not differ between the groups., P. Zach, J. Mrzílková, L. Řezáčová, A. Stuchlík, K. Valeš., and Obsahuje bibliografii
Consider a specific type of fission where psychological continuity takes a branching form, and one of the offshoots comes into being later than the other offshoot. Let us say that the earlier offshoot comes into being in the left branch at t, and the later offshoot comes into being in the right branch at t+1. With regard to the question how many persons are involved in this case, three answers are worth considering: (i) The original subject persists up to t; a distinct person comes into being immediately after t and continues to exist in the left branch; and the third person comes into being in the right branch at t+1. (ii) The original subject persists up to the moment immediately before t+1; a distinct person comes into being at t+1 and continues to exist in the left branch; and the third person comes into being in the right branch at t+1. (iii) The original subject continues to exist in the left branch; a distinct person comes into being in the right branch at t+1. For those who hold that personal identity consists in psychological continuity of some sort, the aforementioned three options exhaust the sensible ways of understanding how one persists in delayed fission. However, I argue that complications arise for each answer. Hence, delayed fission poses a challenge for the psychological approach to personal identity., Uvažujme o specifickém typu štěpení, kde psychologická kontinuita nabývá větvící podoby, a jeden z odnoží vzniká později než jiný odnož. Řekněme, že dřívější odnož vzniká v levé větvi na t, a pozdější odnož vzniká v pravém rameni na t + 1. Pokud jde o otázku, kolik osob je v tomto případě zapojeno, stojí za zvážení tři odpovědi: (i) Původní téma trvá až do t; zřetelná osoba vstoupí do bytí bezprostředně po t a pokračuje existovat v levé větvi; a třetí osoba vzniká ve správné větvi na t + 1. (ii) Původní subjekt trvá až do okamžiku bezprostředně před t + 1; zřetelná osoba vstoupí do bytí u t + 1 a pokračuje existovat v levé větvi; a třetí osoba vzniká ve správné větvi na t + 1. (iii) Původní předmět zůstává v levé větvi; v pravé větvi na t + 1 vstoupí zřetelná osoba. Pro ty, kteří se domnívají, že osobní identita spočívá v psychologické kontinuitě nějakého druhu, zmíněné tři možnosti vyčerpávají rozumné způsoby, jak porozumět tomu, jak člověk v opožděném štěpení přetrvává. Tvrdím však, že komplikace vznikají pro každou odpověď. Zpožděné štěpení tedy představuje výzvu pro psychologický přístup k osobní identitě. Tvrdím, že komplikace vznikají pro každou odpověď. Zpožděné štěpení tedy představuje výzvu pro psychologický přístup k osobní identitě. Tvrdím, že komplikace vznikají pro každou odpověď. Zpožděné štěpení tedy představuje výzvu pro psychologický přístup k osobní identitě., and Huiyuhl Yi
We compared delayed fluorescence (DF) excitation spectrometry with radiocarbon (14C) technique using a monoalgal culture of Chlorella vulgaris grown under natural temperature and irradiance. This was done by monitoring the DF, in parallel to quantum efficiency (QE) and index of radiant energy utilization efficiency (Ψ) as calculated on the basis of carbon uptake measurements by radiocarbon technique. During the diurnal cycle, temperature, irradiance, and chlorophyll (Chl) contents were monitored in the algal culture that was kept in an open transparent plastic tank submerged at the surface of Lake Kinneret, Israel. The DF signal correlated with both the QE (r 2 = 0.869, p<0.01) and Ψ (r 2 = 0.977, p<0.01) during a diurnal cycle. We suggest that, besides the measurement of active Chl and phytoplankton population composition, the DF signal provides additional information on the QE and Ψ in phytoplankton population. and E. Kurzbaum, W. Eckert, Y. Z. Yacobi.